1. Field of the invention
This invention relates to a water vehicle and a directional control device therefor, and is directed more particularly to a water vehicle having at least a portion thereof underwater during travel of the vehicle through water and a directional control device extendible from the vehicle and operative in an underwater environment to maneuver the vehicle.
2. Description of the Prior Art
Current directional control devices for water vehicles are of two basic types, fins and thrusters. Fins typically are mounted at the aft end of the vehicle or, in the case of an underwater vehicle, on the sail or bow. The effect of fins on the directional control of the vehicle is proportional to the flow rate across the fins. Thus, at low speeds the effectiveness of fins is diminished. Thrusters are effective at low speeds because they produce their own flow, but are noisy, consume power, occupy more space, and are more complex and expensive than fins.
There is thus a need for a fin-type control device which is effective at low vehicle speeds.